A hybrid electric vehicle can operate with significantly greater fuel economy in comparison to a corresponding vehicle that is propelled only by an internal combustion engine. Fuel economy improvements of 30% or greater are not uncommon. The cost of hydrocarbon fuels like diesel fuel have prompted some commercial truck users to explore the potential benefit that a hybrid electric vehicle might offer for their particular businesses.
For example, a business, such as an electric utility, that needs to operate electric devices like power tools at remote job sites might consider purchasing a hybrid electric vehicle that can deliver exportable AC power. A different business, such as a frozen or refrigerated food delivery company, may consider purchasing a hybrid electric vehicle having a body with a refrigeration system, with the refrigeration system operated by a compressor using on-board AC power while the vehicle is being driven. Such a vehicle can operate over an extended delivery area in comparison to a refrigerated truck that employs a cold plate technology where the refrigeration system resides in the truck body but operates only when the vehicle is parked and the refrigeration system is plugged into an electric outlet, typically at night. Delivery route time for the latter truck is limited by the length of time for which the cold plate is able to maintain the frozen or refrigerated goods at the proper temperature.
A plug-in hybrid electric vehicle (PHEV) provides a capability that allows the owner/operator to plug the vehicle's electrical system into the electric utility grid to charge the high-voltage hybrid battery pack. This is normally done during nighttime, when there is typically an excess of AC electricity available on the grid and the price per kilowatt-hour is typically at its lowest. In order to make a PHEV most effective, it should have greater battery energy storage capacity than its non-plug-in hybrid counterpart.